JP5469445B2 - COMMUNICATION DEVICE AND SENSOR SYSTEM WITH PROXIMITY SENSOR FUNCTION - Google Patents

Description

  The present invention relates to a communication device with a proximity sensor function and a sensor system.

  In Patent Literature 1, a sensor such as a temperature sensor or a humidity sensor, a signal processing unit that converts a detection value obtained by the sensor into a measurement value, and the obtained measurement value are wirelessly transmitted to a device that uses the measurement value. There is disclosed a wireless sensor device including a transmission circuit unit. The sensor includes a sensor element and a sensor circuit. For example, in the case of a temperature sensor, the sensor element is the thermistor itself, and the sensor circuit is a resistance element that converts the resistance value of the thermistor into a voltage.

  Patent Document 2 discloses a gas meter system including a first device installed indoors and a second device installed outdoors. In this gas meter system, the integrated calculation value of the gas flow rate measured by the first device is measured value display means of the second device via the communication device of the first device and the communication device of the second device. Is displayed. The communication unit of the first device and the communication unit of the second device are configured to be able to perform wired or wireless communication.

  In addition, the first device of Patent Document 2 is externally connected via communication means when an abnormality is detected by security monitoring means (having various sensors such as a gas leak sensor, a heat sensor, and a smoke sensor). Communicate with.

JP 2006-252216 A JP 2009-174895 A

  The device having the sensor means and the communication means can be used in various applications, so that the demand is expected to increase further in the future. For this reason, there are various requests for the apparatus. For example, there is a demand for miniaturization. This is because, for example, restrictions on the installation location of the device can be reduced by downsizing.

  By the way, in the wireless sensor device of Patent Document 1, the sensor and the wireless transmission circuit unit are juxtaposed. For this reason, the space for arranging these configurations affects the size of the wireless sensor device. The same applies to the first apparatus of Patent Document 2 because the gas flow rate measuring means, the security monitoring means, and the communication means are juxtaposed.

  Note that the above-mentioned request for downsizing also applies to an apparatus equipped with a sensor of a type not described in Patent Documents 1 and 2.

  Accordingly, an object of the present invention is to provide a small communication device with a proximity sensor function.

  Another object of the present invention is to provide a sensor system employing the above-described small communication device with a proximity sensor function.

  A communication device with a proximity sensor function according to a first aspect of the present invention includes an oscillation circuit that generates and outputs a basic signal having a predetermined amplitude and a predetermined frequency, and modulates the basic signal with a predetermined modulation method. For outputting the fundamental signal without being modulated, and for outputting the modulated fundamental signal or the unmodulated fundamental signal. A demodulator that further includes an output terminal, an input terminal, a demodulator configured to demodulate and output a signal input to the input terminal according to the predetermined modulation method, and an antenna A switching unit that performs switching between connection / disconnection between the output end of the modulation unit and the antenna and switching between connection / disconnection between the antenna and the input end of the demodulation unit; And in the communication mode in which the antenna performs wireless communication, the processing unit controls the switching unit so that the antenna is connected to only one of the modulation unit and the demodulation unit. In the sensor mode in which the switching control for mode is performed and the antenna is used as the detection electrode of the electric field type proximity sensor, the switching unit is connected to both the modulation unit and the demodulation unit. Sensor mode switching control and non-modulation control for controlling the modulation unit to output the basic signal without modulating the demodulation unit in the sensor mode. A discrimination process for discriminating the presence of an object approaching or separating from the antenna is performed based on a change in amplitude, frequency, or phase of a signal output from.

  The communication device with a proximity sensor function according to the second aspect is the communication device with a proximity sensor function according to the first aspect, wherein the oscillation circuit can generate a plurality of types of signals having different frequencies. Configured to output one of the plurality of types of signals as the basic signal, and the processing unit varies the frequency between the basic signal used in the communication mode and the basic signal used in the sensor mode. Perform frequency control.

  A communication device with a proximity sensor function according to a third aspect is the communication device with a proximity sensor function according to the first or second aspect, wherein the processing unit includes the communication mode and the sensor mode. Is switched in a time-sharing manner.

  A communication device with a proximity sensor function according to a fourth aspect is a communication device with a proximity sensor function according to any one of the first to third aspects, wherein the processing unit is intermittent. Thus, the communication mode and the sensor mode are switched in a predetermined order during the period of one operation state.

  A communication device with a proximity sensor function according to a fifth aspect is the communication device with a proximity sensor function according to any one of the first to fourth aspects, wherein the processing unit A distance derivation process is further performed for deriving a distance between the antenna and the object from the amplitude, the frequency, or the phase value of the signal output from the demodulator in the sensor mode.

  A sensor system according to a sixth aspect includes at least one communication device with a proximity sensor function according to any one of the first to fifth aspects described above, and the at least one proximity sensor function. The at least one communication device with a proximity sensor function transmits a determination result by the determination process to the host device.

  A sensor system according to a seventh aspect is the sensor system according to the sixth aspect, wherein the at least one communication device with a proximity sensor function is a plurality of communication devices with a proximity sensor function, Each of the plurality of communication devices with a proximity sensor function relays the determination result transmitted from the communication device with a proximity sensor function other than itself to the host device.

  Further, a sensor system according to an eighth aspect is the sensor system according to the sixth or seventh aspect, wherein the host device receives the determination result indicating that the object is detected, A notification process is performed.

  According to the first to eighth aspects, the modulation unit, the demodulation unit, and the antenna are connected in the sensor mode. In such a connection form, a capacitor structure formed by the antenna and an object existing in the vicinity of the antenna affects the unmodulated basic signal transmitted from the modulation unit to the demodulation unit. Specifically, when the object approaches or separates from the antenna, the capacitance value of the capacitor structure changes, and as a result, the amplitude, frequency, etc. of the output signal from the demodulator changes. The object is detected using such a change. That is, a proximity sensor called an electric field type or a capacitance type is configured.

  According to this configuration, the modulation unit, the demodulation unit, and the antenna are shared by the communication mode and the sensor mode. For this reason, compared with a device in which a communication component and a sensor component are separately provided and simply juxtaposed, the device can be reduced in size and weight. Moreover, according to such sharing, compared with the mere juxtaposition structure described above, duplicate parts are reduced, so that the apparatus can be provided at low cost and low price. In other words, the proximity sensor function can be imparted to the communication device without significant cost increase.

  Note that the modulation unit may be shared either in a mode in which the entire modulation unit is shared or in a mode in which a part of the modulation unit is shared. It is done. The same applies to the sharing of the demodulation unit.

  In particular, according to said 2nd aspect, interference etc. can be prevented in the environment where the some communication apparatus with a proximity sensor function was installed. More specifically, a signal output from a communication device with a proximity sensor function in a communication mode (more specifically, a transmission mode) is received and detected by another communication device with a proximity sensor function in the sensor mode. Can be prevented. In addition, since the basic signal is output from the antenna even in the sensor mode, the output signal affects the reception operation in another communication device with a proximity sensor function in the communication mode (more specifically, the reception mode). Can be prevented.

  Moreover, according to said 4th aspect, since a communication apparatus with a proximity sensor function will be in an operation state intermittently, power consumption can be reduced. In addition, since both the communication mode and the sensor mode are performed during one operation state period, the processing speed can be improved compared to the case where both modes are performed separately in separate operation state periods. This is because there is a time lag until an operation is actually possible at the beginning of the operation state period, and by performing both the communication mode and the sensor mode during one operation state period, the number of times of the time lag can be reduced. Because it can be reduced.

  Moreover, according to said 6th aspect, since the communication apparatus with a proximity sensor function which can be reduced in size is employ | adopted as mentioned above, there are few restrictions regarding the installation place of a communication apparatus. Thereby, various sensor systems can be provided.

  Further, according to the seventh aspect, a communication device installed outside the wireless communication range of the host device can communicate with the host device via another communication device. For this reason, it is possible to install a communication device in a wider range than a configuration in which each communication device directly communicates with the host device. Therefore, various sensor systems can be provided.

  Moreover, according to said 8th aspect, since it has an alerting | reporting function, the sensor system suitable for the monitoring system represented by the crime prevention system, for example can be provided.

It is a block diagram which outlines the communication apparatus which concerns on 1st Embodiment (transmission mode). It is a block diagram which outlines the communication apparatus which concerns on 1st Embodiment (reception mode). It is a block diagram which outlines the communication apparatus which concerns on 1st Embodiment (sensor mode). It is a wave form diagram which outlines ASK (amplitude shift keying). It is a timing chart which outlines the communication apparatus concerning a 1st embodiment. It is a schematic diagram which outlines the sensor system which concerns on 2nd Embodiment. It is a schematic diagram which outlines the sensor system which concerns on 2nd Embodiment.

<First Embodiment>
1 to 3 are block diagrams outlining the communication device 1 according to the first embodiment. Although the components illustrated in FIGS. 1 to 3 are the same, the drawings are divided for easy understanding of each operation mode described later.

  The communication device 1 is a device having a wireless communication function and a proximity sensor function. For this reason, the said apparatus 1 can be called the communication apparatus 1 with a proximity sensor function, or the sensor apparatus 1 with a communication function. As will be apparent from the description below, the proximity sensor function is provided by a proximity sensor called an electric field type or a capacitance type.

  The operation mode of the communication device 1 includes a communication mode M1 that operates using a wireless communication function and a sensor mode M2 that operates using a proximity sensor function. The communication mode M1 is roughly divided into a transmission mode M1t and a reception mode M1r. Note that the operation mode of the communication apparatus 1 may include other modes, for example, a data processing mode M3 (see FIG. 5 described later).

  The communication device 1 illustrated in FIGS. 1 to 3 includes a modulation unit 20, a demodulation unit 40, an antenna 60, a switching unit 80, and a processing unit 100.

<Modulation unit 20>
Here, the modulation unit 20 is configured to be able to perform signal modulation by ASK (Amplitude Shift Keying) which is an example of a digital modulation method and an example of an amplitude modulation method. In the example of FIGS. 1 to 3, the modulation unit 20 includes an oscillation circuit 21, switching means 22, and a low pass filter (hereinafter also referred to as “LPF”) 23.

  The oscillation circuit 21 generates and outputs a signal (hereinafter also referred to as “basic signal”) S0 having a predetermined amplitude and a predetermined frequency (for example, a frequency selected in advance from a range of 430 MHz or 60 to 200 kHz). It is configured to be able to. The basic signal S0 is used as a carrier wave in the transmission mode M1t. Here, a case where only one type of frequency can be generated by the oscillation circuit 21 is illustrated, but the frequency is not limited to this example (described later).

  The switching means 22 has one end connected to the output end of the oscillation circuit 21 and the other end connected to the input end of the LPF 23. The switching unit 22 is connected to the processing unit 100, and the processing unit 100 performs open / close control, that is, on / off control between the one end and the other end of the switching unit 22. 1 and 2 illustrate the switching means 22 in the off state. In addition, although the switching means 22 is shown by the typical figure symbol in FIGS. 1-3, it can be comprised by various switching elements and switching circuits.

  As outlined in the waveform diagram of FIG. 4, the processing unit 100 performs on / off control of the switching unit 22 according to transmission data, whereby the amplitude of the basic signal S0 is modulated corresponding to the transmission data. 4 illustrates a case where data “0” and “1” correspond to the off state and the on state of the switching means 22, respectively, but the reverse association is also possible.

  The LPF 23 has an input end connected to the other end of the switching means 22 and an output end connected to the switching unit 80. The LPF 23 is configured to pass a signal having a frequency selected as the frequency of the basic signal S0 and to attenuate and remove harmonic components and the like of the selected frequency. In the example of FIGS. 1 to 3, the output end of the LPF 23 corresponds to the output end of the modulation unit 20, and the signal S <b> 1 output from the LPF 23 becomes an output signal from the modulation unit 20.

  When the processing unit 100 performs on / off control of the switching unit 22 according to transmission data as described above (see FIG. 4), the basic signal S0 amplitude-modulated according to the transmission data becomes the output signal S1 from the modulation unit 20. .

  On the other hand, when the processing unit 100 keeps the switching unit 22 in the ON state, the basic signal S0 is output from the modulation unit 20 without being amplitude-modulated. For this reason, it is also possible to output from the modulation unit 20 an unmodulated basic signal S0 (hereinafter also referred to as “no modulation state” or “no modulation”) as the output signal S1. As will be described later, in the sensor mode M2 (see FIG. 3), the unmodulated basic signal S0 is used.

<Demodulation unit 40>
The demodulator 40 is configured to be able to demodulate the input signal S2 in accordance with a modulation scheme (ASK in this case) adopted by the modulator 20. 1-3, the demodulator 40 includes a band-pass filter (hereinafter also referred to as “BPF”) 41, a low noise amplifier (hereinafter also referred to as “LNA”) 42, and a detection circuit. 43, an LPF 44, and an A / D converter (hereinafter also referred to as “ADC”) 45.

  The BPF 41 has an input end connected to the switching unit 80 and an output end connected to the LNA 42. Here, the input end of the BPF 41 corresponds to the input end of the demodulator 40. The BPF 41 is configured to extract a component in a band near the frequency of the basic signal S0 from the signal S2 input to the input end, and output a signal having the extracted frequency component from the output end.

  The LNA 42 has an input end connected to the output end of the BPF 41 and an output end connected to the detection circuit 43. The LNA 42 is configured to amplify the signal input from the BPF 41 and output the amplified signal from the output terminal. Since the signal S2 in the reception mode M1r is weak, the LNA 42 that is a low-noise amplifier is suitable.

  The detection circuit 43 has an input terminal connected to the output terminal of the LNA 42 and an output terminal connected to the LPF 44. The detection circuit 43 is configured to detect the signal input from the LNA 42 according to the ASK method and output a detection result signal from the output terminal. The detection result signal corresponds to a baseband signal corresponding to data included in the signal S2 input to the demodulator 40.

  The LPF 44 has an input end connected to the output end of the detection circuit 43 and an output end connected to the ADC 45. The LPF 44 is configured to attenuate and remove noise in the detection result signal. Thereby, the signal of the detection result can be brought close to the waveform of the data included in the input signal S2 to the demodulator 40.

  The ADC 45 has an input end connected to the output end of the LPF 44 and an output end connected to the processing unit 100. The output end of the ADC 45 corresponds to the output end of the demodulator 40, and the output signal S3 from the ADC 45 becomes an output signal from the demodulator 40. The ADC 45 is configured to convert a signal (analog signal) input from the LPF 44 into a digital signal and output the obtained digital signal from an output terminal.

  Here, the case where ADC45 is comprised with a comparator is illustrated. According to this example, the detection result signal that has passed through the LPF 44 is waveform-shaped by the comparator, whereby the waveform of the data included in the input signal S2 to the demodulator 40 is reproduced. That is, the digital information included in the input signal S2 is obtained as the output signal S3.

<Antenna 60>
The antenna 60 is used for wireless transmission of the signal S1 generated by the modulation unit 20 in the transmission mode M1t (see FIG. 1), and is used for reception of an external wireless signal (radio wave) in the reception mode M1r (see FIG. 2). . Further, as described later, the antenna 60 is used as a detection electrode of the electric field proximity sensor in the sensor mode M2 (see FIG. 3).

<Switching unit 80>
The switching unit 80 is connected to the antenna 60, the output end of the modulation unit 20, and the input end of the demodulation unit 40. The switching unit 80 is connected to the processing unit 100, and under the control of the processing unit 100, switching between connection / disconnection between the antenna 60 and the modulation unit 20 and connection / disconnection between the antenna 60 and the demodulation unit 40 are performed. Disconnection switching is performed.

  In the example of FIGS. 1 to 3, the switching unit 80 includes two switching units 81 and 82 connected in series. Although the switching means 81 and 82 are illustrated with typical graphic symbols in FIGS. 1 to 3, they can be configured by various switching elements and switching circuits. One end of the switching means 81 is connected to the output end of the modulation section 20 (here, the output end of the LPF 23), and the other end of the switching means 81 is connected to one end of the antenna 60 and another switching means 82. The other end of the switching means 82 is connected to the input end of the demodulator 4 (here, the input end of the BPF 41).

  The switching means 81 and 82 are connected to the processing unit 100 and are on / off controlled by the processing unit 100. More specifically, in the transmission mode M1t (see FIG. 1), the switching unit 81 on the modulation unit 20 side is turned on, and the switching unit 82 on the demodulation unit 40 side is turned off. Thereby, the output signal S1 of the modulation unit 20 can be transmitted from the antenna 60. In the reception mode M1r (see FIG. 2), the switching unit 81 on the modulation unit 20 side is turned off, and the switching unit 82 on the demodulation unit 40 side is turned on. As a result, the external signal received by the antenna 60 is transmitted to the demodulator 40.

  In the sensor mode M2 (see FIG. 3), both the switching means 81 and 82 are turned on. Thereby, the operation as a proximity sensor becomes possible as will be described later. Note that both the switching means 81 and 82 can be turned off at the same time, and such a switching state can be employed in, for example, the data processing mode M3 (see FIG. 5).

  Here, in general, for a radio transceiver of a type that shares an antenna for transmission and reception, whether the antenna is connected to the transmission side (ie, the modulation means side) or the reception side (ie, the demodulation means side) Means for switching is provided. The switching unit 80 of the communication device 1 corresponds to such a general switching unit, but differs in the following points.

  That is, according to the above general switching means, the antenna is selectively connected to only one of the modulation means and the demodulation means, and the modulation means and the demodulation means are connected via the antenna. There is no.

  On the other hand, according to the switching unit 80, it is possible to take a state where both the switching means 81 and 82 are turned on as described above (see FIG. 3). For this reason, the switching unit 80 can form a configuration in which both the modulation unit 20 and the demodulation unit 40 are connected to the antenna 60 in addition to a connection configuration by a general switching unit. That is, according to the switching unit 80, the antenna 60 is connected to at least one of the modulation unit 20 and the demodulation unit 40.

  Moreover, according to the switching part 80, it is also possible to take the state from which both the switching means 81 and 82 are turned off as mentioned above.

  It should be noted that a configuration other than the configuration exemplified by the switching means 81 and 82 may be adopted for the switching unit 80 as long as the above-described connection forms among the modulation unit 20, the demodulation unit 40, and the antenna 60 can be realized.

<Processing unit 100>
The processing unit 100 is configured to perform processing such as various calculations and control in the communication device 1. For example, the processing unit 100 can be configured to include a microcomputer (in other words, a microprocessor) and a memory.

  According to this configuration example, various processes performed by the processing unit 100 can be realized by software. More specifically, the microcomputer executes each processing step (in other words, a procedure) described in the program. Thereby, the microcomputer functions as various means corresponding to the processing step, or various functions corresponding to the processing step are realized by the microcomputer. Note that a plurality of microcomputers may be employed, and in this case, a generic name of the plurality of microcomputers corresponds to the above-described microcomputer.

  The memory can be composed of one or a plurality of ROM (Read Only Memory), RAM (Random Access Memory), and rewritable nonvolatile memory (EPROM (Erasable Programmable ROM), etc.), for example. The memory stores various data (in other words, information), a program executed by the processing unit 100, and provides a work area for executing the program.

  Note that various means or various functions realized by the processing unit 100 may be realized by hardware.

  The processing unit 100 is connected to the switching means 22, 81, 82 as described above, and controls on / off of the switching means 22, 81, 82. The processing unit 100 is connected to the ADC 45 and acquires the digital signal S3 from the ADC 45. The processing unit 100 performs various arithmetic processes using information represented by the digital signal S3 and processes related to operation / control in accordance with the information.

<Operation of apparatus 1>
The operation of the communication device 1 is illustrated with reference to the timing chart of FIG. 5 in addition to FIGS.

  According to the example of FIG. 5, the communication device 1 alternately takes the active state MA and the dormant state MB. In other words, the communication device 1 intermittently enters the operating state MA. In the operation state MA, the processing unit 100, the modulation unit 20, and the demodulation unit 40 perform predetermined operations, and in the inactive state MB, the processing unit 100 and the like stop various operations. Such intermittent operation can be performed, for example, according to a timer provided inside or outside the processing unit 100.

  For such intermittent operation, the operation state MA can be continued without providing the suspension state MB. However, the power consumption can be reduced by stopping the operation of the processing unit 100 or the like in the dormant state MB. Here, even if the processing unit 100 or the like stops operating in the dormant state MB, the power consumption can be reduced. However, by adopting a configuration in which the power supply itself to the processing unit 100 or the like is stopped, further power reduction is achieved. be able to.

  In the example of FIG. 5, during the period of the operation state MA, the communication mode M1 (transmission mode M1t or reception mode M1r), sensor mode M2, and data processing mode M3 are switched in a time division manner and selected in a predetermined order. The Note that the order of mode setting in the communication mode M1, the sensor mode M2, and the data processing mode M3 is not limited to the example of FIG.

  FIG. 5 illustrates a case where all three operation modes M1, M2, and M3 are executed during one operation state MA. On the other hand, for example, by performing only one mode M1, M2 or M3 in one operation state MA, the three operation modes M1, M2 and M3 are divided into three operation states MA and executed. It is also possible to do. In such a case, the modes M1, M2, and M3 are executed in a time division manner.

  However, executing a plurality of (here, two or three) modes in one operation state MA contributes to an improvement in processing speed. This is because when power supply is stopped in the dormant state MB, there is a time lag from when the power supply is resumed to when the power supply is actually operable. That is, as the three operation modes M1, M2, and M3 are divided into a plurality of operating states MA, the number of times of the time lag increases until the modes M1, M2, and M3 are terminated.

  Next, each mode M1, M2, M3 will be described.

<Communication mode M1>
As described above, the communication mode M1 is a mode in which the communication device 1 operates using the wireless communication function, and is roughly divided into a transmission mode M1t and a reception mode M1r. FIG. 5 illustrates a case in which the transmission mode M1t is executed in one operation state MA and the reception mode M1r is executed in the other operation state MA in the operation state MA that is continuous across the dormant state MB. However, it is not limited to such an example. For example, a mode in which the transmission mode M1t is continued a plurality of times, a mode in which the reception mode M1r is continued a plurality of times, a mode in which both modes M1t and M1r are executed in a time-sharing manner in one operation state MA, etc. .

  In the communication mode M1, the processing unit 100 controls the switching unit 80 so that the antenna 60 is connected to only one of the modulation unit 20 and the demodulation unit 40 according to signal transmission / reception (switching for communication mode). control).

  Specifically, in the transmission mode M1t (see FIG. 1), the processing unit 100 turns on the switching unit 81 on the modulation unit 20 side and turns off the switching unit 82 on the demodulation unit 40 side. Thereby, the output signal S1 of the modulation unit 20 can be transmitted from the antenna 60. On the other hand, in the reception mode M1r (see FIG. 2), the processing unit 100 turns off the switching unit 81 on the modulation unit 20 side and turns on the switching unit 82 on the demodulation unit 40 side. As a result, the external signal received by the antenna 60 is input to the demodulator 40.

<Sensor mode M2>
The sensor mode M2 is a mode in which the communication device 1 operates as a proximity sensor. In the sensor mode M2, the processing unit 100 controls the switching unit 80 to connect the antenna 60 to both the modulation unit 20 and the demodulation unit 40 (sensor mode switching control). More specifically, the processing unit 100 turns on both the switching unit 81 on the modulation unit 20 side and the switching unit 82 on the demodulation unit 40 side.

  Further, the processing unit 100 controls the modulation unit 20 to output the basic signal S0 without modulation in a state where the modulation unit 20, the demodulation unit 40, and the antenna 60 are connected to each other (non-modulation control). In the case of the example of FIG. 3, as described above, the processing unit 100 keeps the switching unit 22 of the modulation unit 20 in the ON state so that the modulation unit 20 outputs the basic signal S0 in the non-modulation state. It can be controlled.

  The unmodulated basic signal S0 output from the modulator 20 is input to the demodulator 40 as a signal S2, and demodulated by the demodulator 40 operating in the same manner as in the reception mode M1t. Referring to FIG. 4, it is possible to grasp that the basic signal S0 in the unmodulated state is a signal in which “1” is continuous. Therefore, basically, the demodulated signal S3 output from the demodulator 40 is a signal in which “1” continues.

  However, since the antenna 60 is connected to the transmission path from the modulation unit 20 to the demodulation unit 40, the basic signal S0 is affected by the antenna 60 while being transmitted from the modulation unit 20 to the demodulation unit 40. More specifically, since a capacitor structure is formed using the antenna 60 and the object 2 (see FIG. 3) existing in the vicinity of the antenna 60 as electrodes, the demodulator 40 is affected by the capacitor C. The basic signal S0 is input.

  In this case, the shorter the distance between the antenna 60 and the object 2, the larger the capacitance of the capacitor C, and the smaller the amplitude of the signal detected by the demodulator 40, that is, the signal level. In view of this point, when the object 2 approaches the antenna 60, in other words, when the object 2 moves in a direction in which the distance between the object 2 and the antenna 60 decreases, an output signal from the demodulation unit 40 The amplitude of S3 changes to a decreasing tendency. On the contrary, when the object 2 is separated from the antenna 60, in other words, when the object 2 moves in a direction in which the distance between the object 2 and the antenna 60 is increased, the amplitude of the output signal S3 from the demodulation unit 40 Changes to an increasing trend.

  Therefore, the processing unit 100 can determine the presence of the object 2 that approaches or separates from the antenna 60, in other words, the communication device 1, from the change in the amplitude of the output signal S 3 from the demodulation unit 40. (Discriminating process).

  More specifically, since the processing unit 100 acquires the signal S3 output from the demodulation unit 40, it can detect that the signal S3 has transitioned from “1” to “0”. By detecting the state transition from “1” to “0”, the processing unit 100 determines that the object 2 approaching the communication device 1 exists. Conversely, when the processing unit 100 detects that the output signal S3 from the demodulation unit 40 has transitioned from “0” to “1”, the processing unit 100 determines that there is an object 2 separated from the antenna 60.

  The amplitude change of the output signal S3 from the demodulator 40, in other words, the state transition between “0” and “1” can appear in various ways. For example, it is assumed that the amplitude changes during the sensor mode M2. In addition, for example, it is assumed that a situation that leads to a change in amplitude occurs between the end of the preceding sensor mode M2 and the start of the subsequent sensor mode M2 (for example, during the pause state MB). In this case, the amplitude (“0” or “1”) of the signal S3 in the preceding sensor mode M2 is stored in the memory, and in the subsequent sensor mode M2, the amplitude of the signal S3 stored in the memory; A change in the amplitude can be detected by comparing the amplitude of the signal S3 acquired in the subsequent sensor mode M2.

  As described above, in the sensor mode M2, the antenna 60 is used as a detection electrode, the modulation unit 20 is used as a means for generating and outputting a detection basic signal S0, and the demodulation unit 40 is used as a means for detecting an amplitude change of the basic signal S0. Thus, a so-called electric field type or capacitance type proximity sensor is configured.

<Data processing mode M3>
The data processing mode M3 is a mode in which the communication device 1, in other words, the processing unit 100 performs various data processing.

  For example, the determination processing that is executed in the sensor mode M2 may be executed in the data processing mode M3. More specifically, the processing unit 100 may acquire the signal S3 from the demodulating unit 40 in the sensor mode M2 and store the signal S3 in the memory, and perform the determination processing on the stored data in the data processing mode M3. Is possible.

  Further, for example, when the approach or separation of the object 2 is detected in the sensor mode M2, if processing for transmitting the fact to the outside of the communication device 1 is defined in advance, the processing unit 100 performs the next transmission mode M1t. The packet to be transmitted is prepared in the data processing mode M3.

  For example, the processing unit 100 decodes the signal S2 received in the reception mode M1r (demodulated by the demodulation unit 40 to become the signal S3) in the data processing mode M3. Furthermore, when the decoding result is a command requesting to transmit the detection result in the sensor mode M2, for example, the processing unit 100 prepares a packet to be transmitted in the next transmission mode M1t in the data processing mode M3.

  For example, when the signal S2 received in the reception mode M1r is a command related to adjustment of each unit of the communication device 1, the processing unit 100 performs adjustment according to the command.

  Further, for example, the data processing mode M3 may be used as a period for organizing information transmitted in the transmission mode M1t, information received in the reception mode M1r, and information detected in the sensor mode M2 by a predetermined method. Good.

  In the data processing mode M3, the states of the switching means 81 and 82 of the switching unit 80 can be arbitrarily set. For example, both switching means 81 and 82 are turned off.

<Effect>
According to the communication device 1, the modulation unit 20, the demodulation unit 40, and the antenna 60 are shared by the communication mode M1 and the sensor mode M2. For this reason, compared with a device in which a communication component and a sensor component are separately provided and simply juxtaposed, the device can be reduced in size and weight. Further, according to such sharing, compared with the simple juxtaposed structure described above, duplicate parts are reduced, so that the communication device 1 can be provided at a low cost and at a low price. In other words, the proximity sensor function can be imparted to the communication device without significant cost increase.

<Modification 1>
In the above, the case where only one type of basic signal S0 can be generated by the oscillation circuit 21, that is, the case where the frequency of the basic signal S0 is only one type has been illustrated.

  On the other hand, the oscillation circuit 21 may be configured to be able to generate a plurality of types of signals having different frequencies. Such a configuration can be realized, for example, by providing the oscillation circuit 21 with a plurality of oscillation circuits having different oscillation frequencies, or by employing an oscillation circuit with an oscillation frequency adjustment function in the oscillation circuit 21. In this case, one of the plurality of types of signals is output from the oscillation circuit 21 as the basic signal S0.

  By controlling the oscillation circuit 21 by the processing unit 100, it is possible to make the frequency different between the basic signal S0 used in the communication mode M1 and the basic signal S0 used in the sensor mode M2 (frequency control). For example, a signal of 430 MHz can be used as the basic signal S0 in the communication mode M1, and a signal having a frequency selected in advance from the range of 60 to 200 kHz can be used as the basic signal S0 in the sensor mode M2.

  According to such a configuration, it is possible to prevent interference and the like in an environment where a plurality of communication devices 1 are installed. More specifically, a signal (in other words, a radio wave) output from the communication device 1 in the transmission mode M1t is prevented from being received by another communication device 1 in the sensor mode M2 and affecting the detection operation. can do. Further, since the unmodulated basic signal S0 is output from the antenna 60 also in the sensor mode M2, it is possible to prevent the output signal from affecting the reception operation in the other communication device 1 in the reception mode. Can do.

<Modification 2>
In the above description, the ADC 45 is configured with a comparator. In this case, the signal output from the LPF 44 is converted into a binary signal of “0” and “1” in the demodulator 40 and input to the processing unit 100. On the other hand, the ADC 45 may be configured so that the output signal from the LPF 44 is analog / digital converted with a multilevel quantization level. According to this, the processing unit 100 can acquire the value of the amplitude of the signal output from the LPF 44, in other words, the waveform of the signal, and as a result, can acquire the details of the amplitude change of the signal.

  Thereby, the approach / separation of the object 2 can be determined with high accuracy.

  Note that the processing unit 100 can generate the binary signal by performing the same processing as the comparator on the input multilevel signal. According to this, for example, a mode in which a binary signal is used in the reception mode M1t and a multilevel signal is used in the sensor mode M2 can be employed.

  It is also possible to derive the distance between the antenna 60 and the object 2 from the acquired amplitude value.

  For example, the correlation existing between the amplitude value of the signal S3 output from the demodulator 40 and the distance from the antenna 60 to the object 2 may be acquired in advance. Such correlation can be obtained in advance by experiments, for example. Alternatively, for example, the correlation can be obtained in advance by analyzing a circuit model created based on the capacitor structure formed by the antenna 60 and the object 2 and the circuit configuration of the communication device 1. .

  The correlation can be given to the processing unit 100 in the form of an arithmetic expression described in the program, data in a table format, or the like. Accordingly, the processing unit 100 can acquire the distance between the antenna 60 and the object 2 by applying the amplitude value of the signal S3 output from the demodulation unit 40 to the correlation.

  This distance deriving process may be executed in the sensor mode M2, or may be executed in the data processing mode M3.

<Modification 3>
For example, an output adjusting unit that amplifies or attenuates the power of the output signal from the LPF 23 may be added to the modulation unit 20 after the LPF 23. According to this, the power of the signal transmitted from the antenna 60 in the transmission mode M1t can be adjusted, and the power of the signal transmitted from the modulation unit 20 to the demodulation unit 40 in the sensor mode M2 can also be adjusted.

<Modification 4>
Here, in the example of FIGS. 1 to 3, all of the components used in the communication mode M1 are used in the sensor mode M2. However, the components used in the communication mode M1 and the components used in the sensor mode M2 are It may be a configuration shared in part.

  For example, in the configuration in which the oscillation circuit 21 is provided with a plurality of oscillation circuits having different oscillation frequencies as described above, the oscillation circuit for the communication mode M1 and the oscillation circuit for the sensor mode M2 are separately provided. In such a case, a part of the modulation unit 20 is shared by the communication mode M1 and the sensor mode M2.

  That is, for example, the modulation unit 20 may be shared either in a mode in which the entire modulation unit 20 is shared or in a mode in which a part of the modulation unit 20 is shared. The effect is obtained. The same applies to the sharing of the demodulator 40.

<Modification 5>
In the above, ASK is exemplified as the modulation method. However, other modulation methods involving amplitude modulation, for example, AM (Amplitude Modulation), which is an example of an analog modulation method, may be used.

  It is also possible to apply a modulation scheme involving frequency modulation, for example, FSK (Frequency Shift Keying), which is an example of a digital modulation scheme, and FM (Frequency Modulation), which is an example of an analog modulation scheme. is there.

  In this case, in the sensor mode M2, when the distance between the antenna 60 and the object 2 changes, the capacitance of the capacitor C formed by the antenna 60 and the object 2 changes, and as a result, the output signal S3 from the demodulator 40. The frequency of changes. Therefore, the approach / separation of the object 2 can be determined from the frequency change. It is also possible to derive the distance between the antenna 60 and the object 2 from the frequency value.

  It is also possible to apply a modulation scheme involving phase modulation, for example, PSK (Phase Shift Keying) which is an example of a digital modulation scheme.

  In this case, in the sensor mode M2, when the distance between the antenna 60 and the object 2 changes, the capacitance of the capacitor C formed by the antenna 60 and the object 2 changes, and as a result, the output signal S3 from the demodulator 40. The phase of changes. Therefore, the approach / separation of the object 2 can be determined from the phase change. It is also possible to derive the distance between the antenna 60 and the object 2 from the phase change value.

<Second Embodiment>
In 2nd Embodiment, the sensor system which employ | adopted said communication apparatus 1 with a proximity sensor function is illustrated. 6 and 7 are schematic views outlining such a sensor system 5. The sensor system 5 illustrated in FIGS. 6 and 7 includes a plurality of communication devices 1 (here, three communication devices 1 are illustrated) and a host device 3. In the drawings, the communication device 1 with a proximity sensor function is represented as “device with sensor”.

  The host device 3 is configured to be capable of wireless communication with the communication device 1. For example, the host device 3 performs various processes based on information transmitted from the communication device 1. The information transmitted from the communication device 1 to the host device 3 includes, for example, a determination result regarding the approach / separation of the object 2. Further, the host device 3 transmits various information to the communication device 1, for example. Such transmission information includes, for example, a command for requesting transmission of the determination result.

  In the example of FIG. 6, each of the communication devices 1 is installed in a range where wireless communication with the host device 3 is possible (in other words, a range where radio waves can reach). In this case, each communication device 1 can directly communicate with the host device 3. Such a communication format is referred to as a direct communication type.

  In the example of FIG. 7, only one communication device 1 is installed in a range where wireless communication with the host device 3 is possible, and the remaining two communication devices 1 are installed outside the range. Further, each of these three communication devices 1 is installed within a communicable range of other communication devices 1 other than itself. In particular, each communication device 1 relays information transmitted from another communication device 1 other than itself to the host device 1 under the control of the processing unit 100.

  According to such a relay function, for example, the communication device 1 installed outside the wireless communication range of the host device 3 can also communicate with the host device 3 via the other communication device 1. Such a communication format is referred to as a relay communication type.

  In both the direct communication type and the relay communication type sensor system 5, the communication device 1 can be reduced in size as described above, so that there are few restrictions on the installation location of the communication device 1. For this reason, the sensor system 5 can be developed for various uses.

  For example, both the direct communication type and the relay communication type sensor system 5 can be applied to various monitoring systems represented by a security system, for example. For example, when the monitoring system is used to detect that the object 2 stationary in advance at a predetermined position is separated from the position, the communication device 1 is installed in the vicinity of the object 2. More specifically, in the case of a crime prevention system, the communication device 1 is installed on a door, a window, or the like. Further, when the monitoring system is used for detecting a moving object 2, for example, the communication device 1 is installed on the moving path of the object 2. More specifically, in the case of a crime prevention system, the communication device 1 is installed on a passage, a ceiling of a room, a wall, or the like.

  In a monitoring system, particularly a security system, it is preferable that the sensor module can be easily attached to an inconspicuous place. In view of this point, the communication device 1 that is small and light and has few restrictions on the installation location is preferable.

  Here, in the monitoring system, when the host device 3 receives a determination result indicating that the object 2 has been detected from any of the communication devices 1, the host device 3 preferably performs a notification process. Examples of such notification processing include processing for driving notification means such as a buzzer, a light emitter, and a display device provided in advance in the host device 3. In addition, the notification process may be a process in which the host device 3 reports to another device (for example, a communication terminal installed in the police or a security company) by wired communication or wireless communication.

  In particular, according to the relay communication type, since the communication device 1 can be installed in a wider range than the direct communication type, the application application of the sensor system 5 is further expanded.

  For example, by arranging the communication device 1 along a road, the relay communication type sensor system 5 can be applied to a system that investigates the traffic volume, the degree of congestion, and the like on the road. In this case, a vehicle or the like is detected as the object 2. Further, the host device 3 collects the detection results of the respective communication devices 1 and analyzes them by a predetermined method, thereby obtaining the information such as the traffic volume.

  In addition, although the system configuration using the plurality of communication devices 1 is illustrated above, the number of the communication devices 1 included in the sensor system 5 may be one.

DESCRIPTION OF SYMBOLS 1 Communication apparatus with a proximity sensor function 2 Object 3 Host apparatus 5 Sensor system 20 Modulation part 21 Oscillation circuit 40 Demodulation part 60 Antenna 80 Switching part 100 Processing part M1 Communication mode M1t Transmission mode M1r Reception mode M2 Sensor mode MA Operation state MB Sleep state S0 basic signal

Claims (8)

An oscillation circuit that generates and outputs a basic signal having a predetermined amplitude and a predetermined frequency, and is configured to be able to modulate and output the basic signal by a predetermined modulation method; A modulation unit configured to output without modulation, and further including an output terminal for outputting the modulated basic signal or the unmodulated basic signal;
A demodulator configured to include an input terminal, and configured to demodulate and output a signal input to the input terminal according to the predetermined modulation method;
An antenna,
A switching unit that performs switching between connection / disconnection between the output end of the modulation unit and the antenna and switching between connection / disconnection between the antenna and the input end of the demodulation unit;
A processing unit,
In the communication mode in which the processing unit performs wireless communication with the antenna,
Control the switching unit so that the antenna is connected to only one of the modulating unit and the demodulating unit, switching control for communication mode,
In the sensor mode in which the processing unit uses the antenna as a detection electrode of an electric field proximity sensor,
Sensor mode switching control for controlling the switching unit so that the antenna is connected to both the modulation unit and the demodulation unit;
The modulation unit is controlled to output the basic signal without being modulated, and performs non-modulation control.
The processor is
In the sensor mode, from the change in the amplitude, frequency or phase of the signal output from the demodulator, the presence of an object that approaches or is separated from the antenna is performed.
Communication device with proximity sensor function. It is a communication apparatus with a proximity sensor function according to claim 1,
The oscillation circuit is configured to be capable of generating a plurality of types of signals having different frequencies, and outputs one of the plurality of types of signals as the basic signal.
The processing unit performs frequency control in which frequencies are different between the basic signal used in the communication mode and the basic signal used in the sensor mode.
Communication device with proximity sensor function. The communication device with a proximity sensor function according to claim 1 or 2,
The processing unit switches the communication mode and the sensor mode in a time-sharing manner.
Communication device with proximity sensor function. The communication device with a proximity sensor function according to any one of claims 1 to 3,
The processing unit intermittently enters an operating state and switches the communication mode and the sensor mode in a predetermined order during a period of one operating state.
Communication device with proximity sensor function. The communication device with a proximity sensor function according to any one of claims 1 to 4,
The processing unit further includes a distance derivation process of deriving a distance between the antenna and the object from the amplitude, the frequency, or the phase value of the signal output from the demodulation unit in the sensor mode. Do,
Communication device with proximity sensor function. While comprising at least one communication device with a proximity sensor function according to any one of claims 1 to 5,
A host device configured to be able to wirelessly communicate with the at least one communication device with a proximity sensor function;
The at least one communication device with a proximity sensor function transmits a determination result by the determination processing to the host device.
Sensor system. The sensor system according to claim 6,
The at least one communication device with a proximity sensor function is a plurality of communication devices with a proximity sensor function,
Each of the plurality of communication devices with proximity sensor function relays the determination result transmitted from other communication devices with proximity sensor function other than itself toward the host device,
Sensor system. The sensor system according to claim 6 or 7,
When the host device receives the determination result indicating that the object has been detected, the host device performs notification processing.
Sensor system.

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